This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This project characterizes convergence of specific prefrontal cortex (PFC) inputs with the amygdala and temporal cortex in distinct striatal regions and investigates how this system undergoes refinement and reorganization consistent with postnatal milestones of behavioral development. We have currently ordered two rhesus monkeys (3-year-old and 1-year-old) to begin this project in January 2010 using MRI-guided injections of neuroanatomical tracers into the amygdala. We will (a) examine anatomical changes in cortex, striatum, amygdala and hippocampal pathways at the age of birth, 2-4 mo., 6 mo., 1 yr., and 3 years;(b) characterize the specific organization of cortical, amygdala, and hippocampal inputs to the striatum, with a particular focus on the refinement of diffuse projections and the convergence of focal projections;(c) will compare the models of convergent nodal regions across all age groups. Data obtained from such anatomical studies are clinically relevant because infancy through young adulthood is that critical time in which incentive-based learning forms the basis for behavioral guiding rules and the development of habits. Consistent with rapid behavioral development, the prefrontal cortex, amygdala, hippocampus and striatum undergo maturation during postnatal development. This time of developmental growth is associated with vulnerability to stress and the emergence of mental health problems including schizophrenia, depression, obsessive-compulsive disorders and addictions.